Metabolic pathways for glucose and fructose: I synthesis and metabolism of fructose by ovine conceptuses.

Fructose, the most abundant hexose sugar in fetal fluids and blood of sheep and other ungulates and cetaceans, is synthesized from glucose via the polyol pathway in trophectoderm and chorion. However, the cell-specific and temporal expression of enzymes for the synthesis and metabolism of fructose in sheep conceptuses (embryo and placental membranes) and placentomes has not been characterized. This study characterized key enzymes involved in fructose synthesis and metabolism by ovine conceptuses throughout pregnancy. Day 17 conceptuses expressed mRNAs for the polyol pathway (SORD and AKR1B1) and glucose and fructose metabolism (HK1, HK2, G6PD, OGT, and FBP), but not those required for gluconeogenesis (G6Pase or PCK). Ovine placentomes also expressed mRNAs for SORD, AKR1B1, HK1, and OGT. Fructose can be metabolized via the ketohexokinase (KHK) pathway and isoforms, KHK-A and KHK-C, were expressed in ovine conceptuses from Day 16 of pregnancy and placentomes during pregnancy in a cell specific manner: KHK-A protein was more abundant in trophectoderm and cotyledons of placentomes, while KHK-C protein was more abundant in endoderm of Day 16 conceptuses and chorionic epithelium in placentomes. Expression of KHK mRNAs in placentomes was greatest at Day 30 of pregnancy (P < 0.05), but not different among days later in gestation. These results provide novel insights into the synthesis and metabolism of fructose via the uninhibited KHK pathway in ovine conceptuses to generate ATP via the TCA cycle, as well as substrates for the pentose cycle, hexosamine biosynthesis pathway and one-carbon metabolism required for conceptus development throughout pregnancy.

Metabolic pathways of glucose and fructose: II spatiotemporal expression of genes involved in synthesis and transport of lactate in ovine conceptuses.

Lactate, an abundant molecule in fetal fluids and blood of mammalian species is often overlooked as a metabolic waste product generated during pregnancy. Most of the glucose and fructose consumed by ovine conceptuses is converted to lactate, but proteins involved in lactate metabolism and transport have not been investigated. This study characterized total lactate produced by ovine conceptuses throughout gestation, as well as expression of mRNAs and proteins involved in lactate metabolism. Lactate increased in abundance in the uterine lumen during the preimplantation period and was more abundant than pyruvate. The abundance of lactate in allantoic and amniotic fluids increased with advancing days of gestation and most abundant on Day 125 of pregnancy (P < 0.05). Lactate dehydrogenase (LDH) subunits A (converts pyruvate to lactate) and B (converts lactate to pyruvate) were expressed by conceptuses throughout gestation. Lactate is transported via monocarboxylic acid transporters SLC16A1 and SLC16A3, both of which were expressed by the conceptus throughout gestation. Additionally, the interplacentomal chorioallantois from Day 126 expressed SLC16A1 and SLC16A3 and transported lactate across the tissue. Hydrocarboxylic acid receptor 1 (HCAR1), a receptor for lactate, was localized to the uterine luminal and superficial glandular epithelia of pregnant ewes throughout gestation, and conceptus trophectoderm during the peri-implantation period of gestation. These results provide novel insights into the spatiotemporal profiles of enzymes, transporters, and receptor for lactate by ovine conceptuses throughout pregnancy.

Characterization of placentome vascular perfusion in relation to pregnancy associated glycoproteins throughout gestation in pregnant beef heifers.

During pregnancy, blood flow to the uterus changes to support fetal demand. Placentomes serve as vascular attachment sites on the placenta for exchange of gases, nutrients, and metabolic products. Non-invasive methods of ultrasonography and biomarkers have been described to assess placental health and fetal viability. Pregnancy associated glycoproteins (PAGs) are produced by the ruminant placenta and are detected in maternal circulation. In cattle, changes in circulating PAG concentrations are associated with embryonic and fetal outcomes. The objective of this study was to determine the association between placentome blood perfusion and circulating PAG concentrations as they relate to the health of the developing fetus. We hypothesized that placentome perfusion and PAG concentration will be positively correlated and associated with neonatal outcome. A prospective, observational study was designed using 26 pregnant, nulliparous, Angus heifers in which PAG concentration and placentome blood perfusion were assessed throughout gestation, with assessment of calving characteristics following parturition. Placentome blood perfusion was visualized at 30-day intervals via transrectal Doppler ultrasonography with power flow function. Ultrasound images were analyzed using ImageJ software to determine the percent area of perfusion and integrated pixel densities. Venous blood was collected and PAG concentrations were determined via serum PAG enzyme-linked immunoassay. Mean placentome blood perfusion increased as gestation advanced. PAG concentrations demonstrated the expected temporal trend, increasing with gestation length, and were positively linearly correlated with placentome perfusion (P < 0.0001). The relationship identified between circulating PAG concentration and placentome blood perfusion suggests the use of transrectal power flow Doppler ultrasonography as a noninvasive technique to determine placental blood flow morphometrics to assess conceptus wellbeing throughout pregnancy.

Gene expression profile of placentomes and clinical parameters in the cows with retained placenta.

BACKGROUND: Retained placenta (RP) is a prevalent disorder in cattle with many health-related and economic costs for the farm owners. Its etiology has not been clarified yet and there is no definite therapy for this disorder. In this study we conducted RNA-seq, hematologic and histologic experiments to survey the causes of RP development. METHODS: Blood samples were collected from 4 RP and 3 healthy cows during periparturtion period for hematological assessments followed by placentome sampling within 30 min after parturition. Cows were grouped as RP and control in case the placenta was retained or otherwise expelled, respectively. Total RNA was extracted from placentome samples followed by RNA-sequencing. RESULTS: We showed 240 differentially expressed genes (DEGs) between the RP and control groups. Enrichment analyzes indicated immune system and lipid metabolism as prominent over- and under-represented pathways in RP cows, respectively. Hormonal assessments showed that estradiol-17ß (E2) was lower and cortisol tended to be higher in RP cows compared to controls at the day of parturition. Furthermore, histologic experiment showed that villi-crypt junctions remain tighter in RP cows compared to controls and the crypts layer seemed thicker in the placentome of RP cows. Complete blood cell (CBC) parameters were not significantly different between the two groups. CONCLUSION: Overall, DEGs derived from expression profiling and these genes contributed to enrichment of immune and lipid metabolism pathways. We suggested that E2 could be involved in development of RP and the concentrations of P4 and CBC counts periparturition might not be a determining factor.

Relationship of parathyroid hormone-related protein and neonatal mineral metabolism in dairy cow placentas.

Parathyroid hormone-related protein (PTHrP) plays essential roles in placental calcium (Ca) transport, and it has been speculated that PTHrP in the placenta is regulated by calcium-sensing receptors (CaSR). This study clarified the relationship between PTHrP in the placenta of dairy cows and minerals in the fetal blood. Blood samples were obtained from 21 Holstein cows and 17 neonatal calves as well as 12 umbilical veins and arteries during cesarean section. After fetus removal, 13 caruncles and cotyledons were obtained. Concentrations of plasma PTHrP and serum minerals were measured. Real-time polymerase chain reaction (RT-qPCR) analyzed the gene expression of PTHrP and CaSR in the placenta. As a result, serum Ca and inorganic phosphorus concentrations in the neonate, umbilical vein, and artery were significantly higher than in the mother. Additionally, plasma PTHrP was detected in the bovine neonatal jugular vein, umbilical artery, and vein. PTHrP gene expression was significantly higher in the caruncles than in cotyledons; however, CaSR gene expression was higher in the cotyledons than in caruncles. These findings suggest that the PTHrP obtained from the placenta influences Ca homeostasis in the bovine fetus.

Untangling the placentome gene network of beef heifers in early gestation.

The cotyledon and caruncle tissues provide a functional bridge between the fetus and the dam. However, the relationship between these tissues and the transcriptomic profile that underlies the tissue functions remains elusive. Herein we investigate the expression profile of cotyledon and caruncle from nulliparous beef heifers carrying female fetuses at day 83 of pregnancy to identify changes occurring across tissues that contribute to placental function and their tissue-specific roles. We identified 2654 differentially expressed genes [padj ≤ 0.05, abs(log2FC) ≥ 1], including nutrient transporters and paternally imprinted genes. We found key regulators of tissue function and differentiation, including FOXO4, GATA2, GATA3, and HAND1, rewired between the tissues. Finally, we shed light on the over-represented pathways related to immune tolerance, tissue differentiation and remodeling. Our findings highlighted the intricate and coordinated cross-talk between fetal-maternal tissues. They provided evidence of a fine-tuned gene regulatory network underlying pregnancy and tissue-specific function in the bovine placenta.

Effects of nutrient restriction during early or mid-gestation in bovine on placental development and miRNA expression in the cotyledon.

The objective of this study was to determine effects of maternal nutrient restriction (NR) during early or mid-gestation on uterine composition and miRNA expression in cotyledons. Primiparous Angus-cross cows (n = 38) were synchronized and inseminated using male sexed semen, blocked by body condition score and body weight (BW), and assigned to treatments. Animals were fed either: control (CON; gain 1 kg/week) or NR (55% maintenance energy and crude protein requirements) based on BW. An initial set of animals were fed either NR (n = 8) or CON (n = 8) from day 30-110 of gestation. A second set of animals were fed CON (n = 8) d 30-190 (CON/CON); NR (n = 7) day 30-110 followed by CON day 110-190 (NR/CON); or CON (n = 7) day 30-110 followed by NR day 110-190 (CON/NR). Cows were harvested on day 110 or 190 of gestation to collect placental tissues. RNA was isolated from cotyledon samples (3 animals/group) prior to microarray analysis using known Bos taurus microRNA sequences. Relative microRNA abundance was analyzed via ANOVA. Maternal NR increased (P < 0.05) cotyledon weight and total placentome surface area irrespective of gestational day. At day 110 of gestation, 51 microRNAs were reduced while 91 microRNAs observed greater abundance (P < 0.05) in NR verses CON cotyledons. At day 190 of gestation, 40 microRNAs were reduced and 26 microRNAs were increased (P < 0.05) in both NR/CON and CON/NR verses CON cotyledons. Top KEGG pathway analysis included: axon guidance, endocytosis, neuroactive ligand receptor interaction, and MAPK signaling pathway. Early-gestation maternal NR altered microRNA abundance to a greater extent than mid-gestation NR.

Differences in bovine placentome blood vessel density and transcriptomics in a mid to late-gestating maternal nutrient restriction model.

INTRODUCTION: Prenatal development is reliant on a functioning placenta, which can be influenced by maternal nutrition. Moreover, the variation in cotyledonary capacity within an animal has not been fully examined to date. Therefore, the purpose of this study was to determine the effect of (1) placentome size and (2) maternal nutrient restriction on molecular, microscopic, and macroscopic features of bovine placentomes during late gestation. METHODS: Pregnant cows (n = 6) were placed into one of 2 treatments: CON (100% NRC) vs RES (60% of NRC) from day 140 until slaughter at day 240 of gestation. Placentomes of various sizes were perfused to assess macroscopic blood vessel density of the cotyledon. Microscopic imaging and RNA extraction for sequencing was performed. RESULTS: Macroscopic blood vessel density relative to placentome weight was not different (P = 0.42) among small, medium, or large placentomes. Cotyledonary microscopic blood vessel number, area, and perimeter was increased (P < 0.005) in high versus low blood perfusion areas. Differential expressed gene (DEG) analysis showed 209 upregulations and 168 downregulations in the RES group (P ≤ 0.0001). Gene Ontology (GO) analysis showed that downregulated enriched terms were involved in blood vessel and mesenchymal stem cells development, whereas upregulated enriched terms were involved with translation and ribosomal function. DISCUSSION: This study demonstrates that placentome function is uniform across various placentome sizes within an animal. However, microscopic heterogeneity exists within each placentome. Maternal nutrient constraints alter placental transcriptomics which may yield compensatory mechanisms involved in nutrient transport including increased perimeter.

Supplementing N-carbamoylglutamate in late gestation increases newborn calf weight by enhanced placental expression of mTOR and angiogenesis factor genes in dairy cows.

The objective of this study was to investigate whether supplementation with N-carbamoylglutamate (NCG) to cows during late gestation alters uteroplacental tissue nutrient transporters, calf metabolism and newborn weight. Thirty multiparous Chinese Holstein cows were used in a randomized complete block design experiment. During the last 28 d of pregnancy, cows were fed a diet without (CON) or with NCG (20 g/d per cow). The body weight of calves was weighed immediately after birth. Placentome samples were collected at parturition and used to assess mRNA expression of genes involved in transport of arginine, glucose, fatty acid and angiogenesis factors, as well as the mammalian target of rapamycin (mTOR) pathway. Blood samples of calves before colostrum consumption were also collected for the detection of plasma parameters, amino acids (AA) and metabolomics analysis. The newborn weight (P = 0.02) and plasma Arg concentration of NCG-calves was significantly higher (P = 0.05) than that of CON-calves, and the plasma concentrations of urea nitrogen tended to be lower (P = 0.10) in the NCG group. The mRNA abundance of genes involved in glucose transport (solute carrier family 2 member 3 [SLC2A3], P < 0.01), angiogenesis (nitric oxide synthase 3 [NOS3], P = 0.02), and mTOR pathway (serine/threonine-protein kinase 1 [AKT1], P = 0.10; eukaryotic translation initiation factor 4B pseudogene 1 [EIF4BP1], P = 0.08; EIF4EBP2, P = 0.04; and E74-like factor 2 [ELF2], P = 0.03) was upregulated in the placentome of NCG-supplemented cows. In addition, 17 metabolites were significantly different in the placentome of NCG-supplemented cows compared to non-supplemented cows, and these metabolites are mainly involved in arginine and proline metabolism, alanine, aspartate and glutamate metabolism, and citrate cycle. In summary, the increased body weight of newborn calves from the NCG supplemented dairy cows may be attributed to the increased angiogenesis and uteroplacental nutrient transport and to the activated mTOR signal pathway, which may result in the increased nutrient supply to the fetus, and improved AA metabolism and urea cycle of the fetus.

Placental Transcriptome Adaptations to Maternal Nutrient Restriction in Sheep.

Placental development is modified in response to maternal nutrient restriction (NR), resulting in a spectrum of fetal growth rates. Pregnant sheep carrying singleton fetuses and fed either 100% (n = 8) or 50% (NR; n = 28) of their National Research Council (NRC) recommended intake from days 35-135 of pregnancy were used to elucidate placentome transcriptome alterations at both day 70 and day 135. NR fetuses were further designated into upper (NR NonSGA; n = 7) and lower quartiles (NR SGA; n = 7) based on day 135 fetal weight. At day 70 of pregnancy, there were 22 genes dysregulated between NR SGA and 100% NRC placentomes, 27 genes between NR NonSGA and 100% NRC placentomes, and 22 genes between NR SGA and NR NonSGA placentomes. These genes mediated molecular functions such as MHC class II protein binding, signaling receptor binding, and cytokine activity. Gene set enrichment analysis (GSEA) revealed significant overrepresentation of genes for natural-killer-cell-mediated cytotoxicity in NR SGA compared to 100% NRC placentomes, and alterations in nutrient utilization pathways between NR SGA and NR NonSGA placentomes at day 70. Results identify novel factors associated with impaired function in SGA placentomes and potential for placentomes from NR NonSGA pregnancies to adapt to nutritional hardship.

Morphology of placentome in Korean water deer Hydropotes inermis argropus.

The placenta of the Korean water deer was anatomically examined to accumulate basic information regarding its reproductive system. The convex placentomes with five to nine well-developed pedicles were observed in the whole uterine horns, and therefore, the placenta was classified as oligocotyledonary. The evidence indicating the migration of binucleate cells (BNCs) from trophectoderm to the uterine epithelium led to the histological classification of the placenta as synepitheliochorial. The number of fetuses was markedly higher than that in other ruminant species. However, the number of placentomes was found to be similar to the other Cervidae species. Therefore, these results suggest that the Korean water deer may possess special mechanisms or structures at the fetus attachment site to maintain this unusally high number of fetuses.

Effects of fetal and maternal genotype on placentome morphology in sheep.

Both maternal and fetal genotypes contribute to conceptus development. The objective was to determine how placentome number, size, and type and fetal weight was influenced after reciprocal embryo transfer in Columbia and Romanov sheep. Reciprocal embryo transfer was conducted between Columbia and Romanov ewes where a single embryo was transferred into Romanov and Columbia recipients [Romanov embryo in a Romanov uterus (RinR, n = 9); Romanov embryo in a Columbia uterus (RinC, n = 7); Columbia embryo in a Columbia uterus (CinC, n = 8); Columbia embryo in a Romanov uterus (CinR, n = 4)]. On day 130 of gestation, fetuses were weighed and placentomes were morphologically typed, weighed, and measured. Regardless of maternal genotype, Romanov fetuses were smaller (P < 0.05) compared to Columbia fetuses. Moreover, CinC fetuses were larger (P < 0.05) than CinR fetuses. There was a tendency (P = 0.12) for a fetal by maternal genotype interaction on total placentome weight, but main effects were significant for fetal genotype (P = 0.04) and maternal genotype (P < 0.01). The number of Type A placentomes was greater than any other types. Type A placentomes had a greater (P < 0.05) contribution to total placentome weight within the Romanov uterus, or when associated with a Romanov fetus, than within the Columbia breed, in which placentome type was evenly distributed. The hypothesis that the Romanov uterus would limit the growth of a Columbia conceptus is accepted; however, the Romanov conceptus did not experience augmented growth when transferred into a Columbia uterus as predicted.

Identification of Pathways Associated with Placental Adaptation to Maternal Nutrient Restriction in Sheep.

Maternal nutrient restriction impairs placental growth and development, but available evidence suggests that adaptive mechanisms exist, in a subset of nutrient restricted (NR) ewes, that support normal fetal growth and do not result in intrauterine growth restriction (IUGR). This study utilized Affymetrix GeneChip Bovine and Ovine Genome 1.0 ST Arrays to identify novel placental genes associated with differential fetal growth rates within NR ewes. Singleton pregnancies were generated by embryo transfer and, beginning on Day 35 of pregnancy, ewes received either a 100% National Research Council (NRC) (control-fed group; n = 7) or 50% NRC (NR group; n = 24) diet until necropsy on Day 125. Fetuses from NR ewes were separated into NR non-IUGR (n = 6) and NR IUGR (n = 6) groups based on Day 125 fetal weight for microarray analysis. Of the 103 differentially expressed genes identified, 15 were upregulated and 88 were downregulated in NR non-IUGR compared to IUGR placentomes. Bioinformatics analysis revealed that upregulated gene clusters in NR non-IUGR placentomes associated with cell membranes, receptors, and signaling. Downregulated gene clusters associated with immune response, nutrient transport, and metabolism. Results illustrate that placentomal gene expression in late gestation is indicative of an altered placental immune response, which is associated with enhanced fetal growth, in a subpopulation of NR ewes.

The expression of hypoxia-inducible factor-1 alpha in primary reproductive organs of the female yak (Bos grunniens) at different reproductive stages.

The yak (Bos grunniens) is the most important livestock animal in high-altitude regions owing to its prominent adaptability to cold conditions, nutritional deficiencies and hypoxia. The reproductive organs exhibit different histological appearances and physiological processes at different reproductive stages. Hypoxia-inducible factor-1 alpha (HIF-1α) is the regulatory subunit of HIF-1 that crucially regulates the response to hypoxia in mammalian organisms. The goal of our study was to investigate the expression and distribution of HIF-1α in the primary yak reproductive organs at different reproductive stages. Samples of the ovary, oviduct and uterus of 15 adult female yaks were collected and used in the experiment. The expression and localization of HIF-1α proteins and mRNA were investigated using quantitative real-time polymerase chain reaction (qRT-PCR), Western blot (WB) and immunohistochemistry (IHC). The results indicated that the expression of HIF-1α protein in the ovary was higher during the luteal phase than during the follicular phase and gestation period (p < .05). In the oviduct, HIF-1α protein was also more highly expressed during the luteal phase than during the follicular phase and gestation period (p < .01). However, in the uterus, the HIF-1α protein had stronger expression during the gestation period than during the follicular phase (p < .01) and luteal phase (p < .05). The expression of HIF-1α mRNA was similar to that of its protein. Immunohistochemical analysis revealed intense immunostaining of HIF-1α proteins in the follicular granulosa cells, granular luteal cells, villous epithelial cells of the oviduct, endometrial glandular epithelium and luminal epithelium, foetal villous trophoblast, and epithelia of caruncular crypts. This study showed that the expression of HIF-1α in the ovary, oviduct and uterus varies according to the stage of the reproductive cycle. This implies that HIF-1α plays an important role in regulating the stage-specific physiological function of yak reproductive organs under hypoxic environments.

Placentation and hormonal maintenance of pregnancy in the impala (Aepyceros melampus).

INTRODUCTION: The impala is a widely distributed African ungulate. Detailed studies of the placenta and ovaries in impala undertaken in the 1970s did not address the endocrine functions of the placenta. METHODS: The uteri of 25 pregnant impala estimated to be between 49 and 113 days of the 190 day gestation were examined grossly, histologically and immunohistochemically. RESULTS: A single corpus luteum was present in either maternal ovary but the conceptus was always situated in the right uterine horn. The fetal membranes extended to the tips of both uterine horns. The amnion was in intimate contact with, but not fused to, the allantochorion. Placentation was typically ruminant with fetal macrocotyledons attached to the rows of maternal caruncles. The fetal villi were highly branched, especially in the centre of each placentome where the attenuated maternal epithelium lining the placental crypts was absent in some places. Both the corpus luteum and the uninucleate trophoblast cells of the interplacentomal allantochorion stained strongly for 3-ß hydroxysteroid dehydrogenase, and progestagen concentrations in allantoic and amniotic fluids increased significantly as gestation progressed, with a tendency to do likewise in maternal serum. Binucleate trophoblast cells stained positively for bovine placental lactogen, but neither the placenta nor the maternal corpus luteum showed evidence of oestrogen synthesis. DISCUSSION: Despite exhibiting the same basic type of placentation, both the gross and histological structure of the impala placenta, along with its immunohistochemical properties, demonstrates that great variation exists across ruminant placentas.

Technical note: Relationship between placentome location and gene expression in bovine pregnancy.

A novel, non-terminal surgical procedure to remove a single placentome from the pregnant ewe for gene expression and histological analyses was recently developed in our laboratory. This technique allows for evaluation of nutritional insults on placental development at more than one stage of gestation using a single animal. Early attempts to develop a similar technique in cattle were met with complications due to inaccessibility of the gravid uterine horn because of its location and mass. One alternative is to collect a placentome from the contralateral uterine horn; however, the question remains as to whether gene expression varies among placentomes based on location relative to the fetus. Pregnant heifers were maintained on forage during early gestation and later moved into pens with a Calan gate system (American Calan, Northwood, NH). On gestational day (GD) 158, five heifers were assigned to receive a hay-based diet formulated to meet 100% of NRC requirements, and five heifers were fed 70% of NRC requirements until necropsy on GD244. At necropsy, a single representative placentome was selected for analysis from the antimesometrial side: (1) of the gravid uterine horn central to the amnion, (2) over the allantois immediately adjacent to the amnion, (3) in the tip of the gravid uterine horn, and (4) in the tip of the contralateral uterine horn. Mean placentome weight was greater (P < 0.05) for locations central to the amnion and allantois compared to locations within the tips of the ipsilateral and contralateral horns, respectively. Gene expression for angiogenic factors (FGF2, ODC1, VEGFA, and FLT1), nutrient transporters (SLC7A1 and SLC2A1), and factors associated with hormone action (ESR1, IGF1, IGFBP3, CSH1, and PAG1) were unaffected (P > 0.05) by dietary treatment or location of the placentome. Results indicate that location of the placentome in relation to the fetus does not impact gene expression, enhancing the efficacy of nonterminal methodologies for sampling gene expression in placentomes.

Gene expression profiles of bovine uninucleate trophoblast cells and trophoblast giant cells: a data note.

OBJECTIVES: In the bovine placenta, intimate fetomaternal contact is restricted to placentomes. Within the placentomes fetal chorionic villi interdigitate with corresponding maternal caruncular crypts. The trophoblast epithelium covering the chorionic villi consists of 80% uninucleate trophoblast cells (UTCs) and 20% trophoblast giant cells (TGCs). TGCs migrate toward the endometrium and fuse with endometrial cells to form short-lived fetomaternal hybrid cells. Thereby the TGCs transport molecules of fetal origin across the placental barrier into the maternal compartment. The UTC/TGC ratio is constant during pregnancy because UTCs can differentiate into new TGCs to replace spent TGCs. However, our understanding of this differentiation process was sparse. Therefore, we collected the data to study the gene expression profiles in UTCs and TGCs and to identify differently expressed genes between the two trophoblast cell populations. Using Gene Ontology analysis, we wanted to identify biological processes and pathways that play an important role in the differentiation of UTCs into TGCs. DATA DESCRIPTION: Bovine placentas were from days 118 to 130 of gestation. We obtained virtually pure UTCs and TGCs using a fluorescence-activated cell sorting (FACS) method. Total RNA was extracted from the UTC and TGC isolates, labeled and hybridized to Affymetrix Bovine Gene 1.0 ST Arrays.

FTY720, a sphingosine analog, altered placentome histoarchitecture in ewes.

BACKGROUND: The lysosphingolipid, sphingosine-1-phosphate, is a well-described and potent pro-angiogenic factor. Receptors, as well as the sphingosine phosphorylating enzyme sphingosine kinase 1, are expressed in the placentomes of sheep and the decidua of rodents; however, a function for this signaling pathway during pregnancy has not been established. The objective of this study was to investigate whether sphingosine-1-phosphate promoted angiogenesis within the placentomes of pregnant ewes. Ewes were given daily jugular injections of FTY720 (2-amino-2[2-(- 4-octylphenyl)ethyl]propate-1,3-diol hydrochloride), an S1P analog. RESULTS: FTY720 infusion from days 30 to 60 of pregnancy did not alter maternal organ weights nor total number or mass of placentomes, but did alter placentome histoarchitecture. Interdigitation of caruncular crypts and cotyledonary villi was decreased, as was the relative area of cotyledonary tissue within placentomes. Also, the percentage of area occupied by cotyledonary villi per unit of placentome was increased, while the thickness of the caruncular capsule was decreased in ewes treated with FTY720. Further, FTY720 infusion decreased the number and density of blood vessels within caruncular tissue near the placentome capsule where the crypts emerge from the capsule. Finally, FTY720 infusion decreased asparagine and glutamine in amniotic fluid and methionine in allantoic fluid, and decreased the crown rump length of day 60 fetuses. CONCLUSIONS: While members of the sphingosine-1-phosphate signaling pathway have been characterized within the uteri and placentae of sheep and mice, the present study uses FTY720 to address the influence of S1P signaling on placental development. We present evidence that modulation of the S1P signaling pathway results in the alteration of caruncular vasculature, placentome architecture, abundance of amino acids in allantoic and amniotic fluids, and fetal growth during pregnancy in sheep. The marked morphological changes in placentome histoarchitecture, including alteration in the vasculature, may be relevant to fetal growth and survival. It is somewhat surprising that fetal length was reduced as early as day 60, because fetal growth in sheep is greatest after day 60. The subtle changes observed in the fetuses of ewes exposed to FTY720 may indicate an adaptive response of the fetuses to cope with altered placental morphology.

Evolution of placentation in cattle and antelopes.

Bovids have enjoyed great evolutionary success as evidenced by the large number of extant species. Several important domestic animals are from this family. They derive from both subfamilies: cattle and their kin belong to Bovinae and sheep and goats to Antilopinae. The premise of this review, therefore, is that evolution of reproduction and placentation is best understood in a context that includes antelope-like bovines and antelopes. Many key features of placentation, including hormone secretion, had evolved before bovids emerged as a distinct group. Variation nevertheless occurs. Most striking is the difference in fusion of the binucleate trophoblast cell with uterine epithelium that yields a transient trinucleate cell in bovines and many antelopes, but a more persistent syncytium in wildebeest, sheep and goat. There is considerable variation in placentome number and villus branching within the placentome. Many antelopes have right-sided implantation in a bicornuate uterus whilst others have a uterus duplex. Finally, there has been continued evolution of placental hormones with tandem duplication of PAG genes in cattle, differences in glycosylation of placental lactogen and the emergence of placental growth hormone in sheep and goats. The selection pressures driving this evolution are unknown though maternal-fetal competition for nutrients is an attractive hypothesis.

Placentation in the Blue Wildebeest (Connochaetes taurinus).

INTRODUCTION: The wildebeest is a populous African ungulate, but despite its wide distribution within that continent few reports exist on the structure and endocrine functions of its placenta. METHODS: The pregnant uteri of 43 Blue Wildebeest estimated to be at less than 70 days of the 8 month gestation period were examined grossly and histologically. RESULTS AND DISCUSSION: The cervix divided into left and right components which eliminated any connection between the uterine horns and limited conceptus development and placentation to the single ipsilateral horn. The placenta was typically ruminant synepitheliochorial macrocotyledonary with numerous flat placentomes developing in the gravid horn. Appreciable quantities of exocrine secretion were accumulated in the lumen of both gravid and non-gravid uterine horns and proliferation of the trophoblast into presumptive villi was evident between the placentomes. The single corpus luteum of pregnancy persisted unchanged during the period of gestation monitored and the mononuclear trophoblast cells of the intercotyledonary, but not the cotyledonary, allantochorion stained strongly for 3-ß hydroxysteroid dehydrogenase indicating their likely secretion of progesterone. The binucleate trophoblast cells stained positively with antisera raised against placenta-associated glycoprotein and bovine placental lactogen. Neither the maternal corpus luteum or the allantochorion showed immunohistochemical staining for cytochrome P450 aromatase.